Waves In Sunspots Research Articles

Alfven wave propagation in a density gradient in sunspots

view Abstract Citations (12) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Alfvén wave propagation in a density gradient in sunspots. Geronicolas, E. A. Abstract In view of the possible generation of Alfven waves in sunspots, a calculation is presented which estimates the ratio of the upward to the downward Alfven-wave flux in sunspots. Only a slight downward preferential propagation is found, so that sufficient Alfven cooling predicts high turbulent umbral velocities, of the order of 3 km/s. Publication: The Astrophysical Journal Pub Date: February 1977 DOI: 10.1086/155008 Bibcode: 1977ApJ...211..966G Keywords: Density Distribution; Magnetohydrodynamic Waves; Sunspots; Thermomagnetic Cooling; Wave Propagation; Wave Reflection; Astronomical Models; Convective Flow; Energy Transfer; Motion Stability; Photosphere; Radiative Transfer; Solar Magnetic Field; Wave Equations; Solar Physics full text sources ADS |

The flux of Alfven waves in sunspots

Under the assumption that the horizontal velocities observed in the sunspot photosphere are caused by Alfven waves, the flux of these waves in the photosphere is found to be equal to 20--50 percent of the missing sunspot flux or 2--3 times the spot's flux of electromagnetic radiation. Since the downward- moving Alfven wave flux is likely to be similar to the upward-moving flux, this observation is consistent with the hypothesis that spots are cooled by their strong emission of Alfven waves.

Thermal Generation of Hydromagnetic Waves in Sunspots

Thermal Generation of Hydromagnetic Waves in Sunspots

ALFVÉN Waves in Sunspots

Model of nonradiative energy transport in sunspots, in which Alfven waves generated in convectively unstable layer propagate upward into overlying stable layer